Biochips for diagnosing and analyzing bio-samples easily and rapidly have been developed. In the biochips, a method of injecting only the bio-samples and a method of injecting various reagents in sequence are used. The former method has a simple form, but may not be applied to diagnosis and analysis requiring a complicated biochemical reaction. The latter method can perform the complicated reaction to apply various analysis protocols, but additionally requires a complicated driving device for storing and supplying the reagents.
In recent trends of the development of biochips, the development of highly functional biochips having high sensitivity, quantification, reproducibility, simultaneously various analyses, and the like has been required and become mainstream. A lab-on-a-chip type biochip which sequentially performs preprocessing, analysis, and measurement of the sample in one chip has been developed. As described above, in order to develop a highly functional lab-on-a-chip type biochip, reproducible implementation of the complicated reaction protocol is required and may be performed by sequential, quantified, and automated supply of the reagent.
Until now, in most lab-on-a-chips, a method has been used, in which necessary reagents are stored outside and supplied to the lab-on-a-chips by an external pumping device. The aforementioned storing and supplying method of the reagents has a problem in that the external device becomes complicated and enlarged. In order to remove the external pumping device, a type in which a micro pump is installed on the lab-on-a-chip has been developed, but there are problems in that a complicated process and additional costs for installing the micro pump on the chip are required and integration of the micro pump on the chip with other elements is difficult, and there is a problem in that the reagent cannot be stored.
In order to solve the problems, several techniques of storing a reagent on a lab-on-a-chip in the related art are proposed. One method is a method in which a chamber for storing a reagent is installed on a chip and sealed after injecting the reagent therein. In this case, an inlet of the reagent and a minute passage connected with the storing chamber need to be sealed, which is mainly implemented by a micro valve or a phase change material. However, process and control operation for opening and closing the minute passage is a little complicated. Another method is a method in which a pouch type reagent storage is adhered on a chip. In this case, by pressurizing the pouch manually or by a mechanical apparatus, reproducibility of flow may be lowered when supplying the reagent, and an additional mechanical control is required.
As described above, in order to store the reagent, homeostatic maintenance of the storage liquid, low-priced implementation, a simple operation, a reproducible supply of the reagent, and the like are required. However, in the related art, there is a limit in satisfying the required conditions.